Legacy analog systems that have traditionally communicated over public switched telephone networks to communicate with service providers have become antiquated due to improvement to telecommunications networks. For example, packet networks that were developed for Internet communications have evolved to enable voice over Internet Protocol (VoIP) telephone communications using data packets to communicate speech. Having the ability to use packet networks to communicate both voice and data, consumers have begun canceling conventional public-switched telephone network telephone services to exclusively use packet network communications services via a digital subscriber line (DSL) or cable network services for Internet and telecommunications services.
One problem that exists for consumers who have legacy analog security systems or other analog self-interacting systems is that these analog systems require analog loop access network infrastructure. Because of the migration of the telecommunications networks from PSTN to packet based networks, digital systems that are compatible with packet based networks are replacing the legacy analog systems. However, replacement of the legacy analog systems with digital systems is expensive for consumers and security service providers.
FIG. 1 is an illustration of an exemplary configuration of a residential network 100 that includes telecommunications devices 102, Internet access devices 104, and analog home security system 106. More specifically, the telecommunications services may include one or more telephones 108a-108b and fax machine 110, for example. A docking station 113 may be utilized to provide wireless communications within the residential location. A computing device 112, such as a personal computer, and modem 114 may be used for Internet access. A telephone line distribution box 116 may be connected to the modem 114, docking station 113, telephone 108b, and fax machine 110. A security system 106 may include one or more sensors 118 that are disposed within the residential location for sensing intruders. A telephone line distribution box 120 or DMARK, as understood in the art, may be used for communicating with the security system 106 and for communicating communications, such as telecommunications and Internet access communications, from the residential location. As shown, the service provider telephone line distribution line 120 is connected to the PSTN 122 or other time division multiplexing (TDM) network. The communications shown are analog communications that use two wire lines for connecting the security system 106 and telephone line distribution box 116.
In operation, when not in a security condition, the analog security system 106 provides direct connection between the telephone line distribution box 116 and the service provider telephone line distribution box 120. During a security event, the security system 106 disconnects the house side through the operation of an internal relay switch (not shown). A security event, therefore, prevents use of the telephone 108b or computing device 112 that may be important to use during a security event to contact authorities in addition to the security service provider being contacted by the analog security system 106. The security event further prevents dial-up access services, such as pay-per-view cable boxes and satellite receivers. After being connected to the service provider telephone line distribution box 120, the security system 106 dials out to connect with a security monitoring facility 124. Upon connecting with the security monitoring facility 124, a hand-shaking procedure is performed for synchronization purposes and the security system 106 sends information, including the calling number and security cause of the event through dual-tone multiple frequency (DTMF) tones. Upon receiving a confirmation from a security monitoring facility 124, the security system 106 restores connection to the house, telephones and other devices via the relay switch.
FIG. 2A is a screen shot 200 of signaling collected by a signal analyzer 126 (FIG. 1) from the security system 106 communicating with the service provider telephone line distribution box 120. In one embodiment, the signal analyzer 126 may be a TSA-6000 model used for capturing analog signals communicated over a telephone line. A graph 202 shows a signal with a number of different events. The graph 202 includes alternating current (AC) coupled signaling of the security system. FIG. 2B shows a graph 202b of direct current (DC) coupled signaling of the security system 106. An alarm off-hook event 204 occurs and causes a DC voltage to drop from 50 volts to 0 volts. An alarm activated event 206 (FIG. 2A) occurs after the alarm off-hook event 204. In response to the alarm activated event 206, a dial tone 208 is provided to the security system 106 (FIG. 1). The security system 106, in receiving the dial tone 208, prevents the telephone monitoring distribution box 116 from receiving communications from the PSTN 122, thereby preventing telecommunications and Internet communication services. The dial tone 208 lasts for approximately 2 seconds, whereupon the security system 106 generates a DTMF signal 210 including data representative of a telephone number. The telephone number is used for calling the security monitoring facility 124 that manages and monitors the security system 106. As understood in the art, ringback signals 212a and 212b (collectively 212) are received by the security system 106. The ringback signals 212, as measured in this event, have a frequency at 440 Hz with signal strength of −32.8 dBm. As shown in FIG. 2B, the DC signal 214 is set at approximately 5 volts during operation of the security system 106.
When the security monitoring facility 124 picks up the call from the security system 106, an acknowledgement tone 216, which lasts for approximately one second and has the frequency of 1.4 KHz and an amplitude or signal strength of −29.4 dBm, is received by the security system 106. After the acknowledgment tone 216, two clear-to-send (CTS) tones 218a and 218b (collectively 218) are received by the security system 106 from the security monitoring facility 124. The CTS tones 218a and 218b, as measured in this event, have frequencies at 1.4 KHz and 2.3 KHz at amplitudes −29.4 dBm and −31.8 dBm, respectively. These CTS tones also have durations less than approximately 150 milliseconds (ms). In response to receiving the CTS tones 218 from the security monitoring facility 124, the security system 106 communicates a telephone number associated with the location of the security system 106 in the first ten digits of a DTMF signal to 220 and event description data in six digits following the ten digit telephone number in the DTMF signal 220. As shown, the telephone number is 403-918-1134 and the event description is 000015, which, in one embodiment, indicates that a front door has been opened. An acknowledgment signal 222, which may have the same parameters as the acknowledgement signal 216 is generated by the security monitoring facility 124 and received by the security system 106. In response to the security system 106 receiving the acknowledgement signal 222, the security system 106 goes back on hook at 224 (FIG. 2B) and telephone and Internet communications are restored to the household.
As shown in the graph 202a, there are several different types of signals that are communicated between the security system 106 and security monitoring facility 124. These signals include dial tone signals, ringback signals, single tone signals (e.g., CTS signals), and DTMF signals. Because some of the signals, such as ringback signals 212, acknowledgment signals 216 and 222, and CTS signals 218, have such low amplitudes (e.g. below −25 dBm), conventional analog to packet networks adapters are incapable of operating with analog security systems or other analog systems that have signal levels that are low or short (e.g. less than about 150 milliseconds). One reason why conventional adapters do not operate on signals below −25 dBm or on signals below 150 ms is that the ANSI/TIA-1063 standard for analog ports of packet-based user-premises terminal adapters specifies otherwise.